The present invention relates to generating style sheets for use with markup language documents.
Style sheets are used to give a common look to a collection of documents. A style sheet contains codes (generally but not necessarily found in one document) that specify formatting for the parts of a document—such as body text, headings, list items, quotes, and so on. Generally, style sheets and documents are in electronic form. With style sheets, the content of a document can be separated from its presentation.
Cascading Style Sheets (CSS) is a style sheet mechanism that extends the HyperText Markup Language (HTML). CSS enables the precise placement of HTML document elements and the precise selection of fonts in HTML documents. CSS can be used by a Web (World Wide Web) page designer to give a common look and feel to large number of documents.
The Cascading Style Sheets, level 1 (CSS1) standard is a W3C (World Wide Web Consortium) Recommendation. It describes the CSS language as well as a simple visual formatting model. The CSS, level 2 (CSS2) standard builds on CSS1 and adds support for media-specific style sheets (e.g., printers and aural devices), downloadable fonts, element positioning and tables. CSS1 is a simple style sheet mechanism that allows authors and readers to attach style (e.g., fonts, colors and spacing) to HTML documents. The CSS1 language is human readable and writable, and expresses style in common desktop publishing terminology. One of the fundamental features of CSS is that style sheets cascade; authors can attach a preferred style sheet, while the reader may have a personal style sheet to adjust for human or technological handicaps. CSS2 is a style sheet language that allows authors and users to attach style (e.g., fonts, spacing, and aural cues) to structured documents (e.g., HTML documents and XML applications).
Other style sheet languages exist as well. For example, the Extensible Stylesheet Language (XSL) Specification, a work in progress of the W3C, defines a language for expressing stylesheets. An XSL stylesheet specifies the presentation of a class of XML documents by describing how an instance of the class is transformed into an Extensible Markup Language (XML) document that uses the formatting vocabulary.
Systems exist that can generate a style sheet from a source document. Generally, such systems are limited to particular file formats, i.e., electronic representations of the source document, or generate style sheets that are specific to the source document and therefore not easily usable by a human user for preparing new documents.